Electric switch.



G. A. BURNHAM.

ELECTRIC SWITCH.

APPLICATION FILED JUNE 17, 1911.

1,015,613. Patented Jan.23, 1912.

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ELECTRIC SWITCH.

APPLICATION FILED JUNE 17, 1911.

1,015,613, Patented Jan.23, 1912.

4 SHEETS-SHEET 2.

Witnesse s 1192- 36 lnbento'r G. A. BURNHAM.

ELECTRIC SWITCH. v APPLIOATION FILED JUNE 17, 911. 1,015,61 3. I Patented Jan. 23, 1912 4 SHEETS-SHEET 3.

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G. A. BURNHAM.

ELECTRIC SWITCH. APPLICATION FILED JUNE 17, 1911.

1,015,613, Patented Jan.23, 1912.

4 SHEETS-SHEET 4.

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Witnesseslnwnzor;

M z MW 1 UNITED STATES PATENT onnrou;

GEORGE A. BURNHAM, OIE. SAUGUS, MASSACHUSETTS, ASSIGNOR TO S. B. CONDIT, JR.,

' 0F BOSTON, MASSACHUSETTS.

ELECTRIC SWITCH;

T 0 all whom it may concern: 1

Be it known that I, GEORGE A. BURNHAM, a citizen of the United States, residing at Saugus, in the county of Essex and State of Massachusetts, have invented an Improvement in Electric Switches, of which the'following is a specification.

This invention relates to electric-switches for circuits carrying high power currents and the invention is embodied in a switch of the oil type having main and auxiliary switches.

Ordinarily the main switches are made of full current-carrying capacity, and are designed and intended to carrythe'current, and the auxiliary switches are made of partial current-carrying capacity, and are designed and intended to serve as the circuitbreaking switches,',and the movable members of said main and auxiliary switches are operated to break thecircuit succssively, the movable switch-members, disengaging the stationary main switch-members in advance of the movable switch-members disengaging the' stationary auxiliary switchmembers. By and during the operation of each movable switch-member the oil surrounding it is disturbed, sometimes violently, and when arranged near together and operated one in advance of theother, the operation of the'second member occurs while the oil near it is being disturbed by the first member, and the efficiency of the oil as a means to reduce the arc and to dissipate the heat energy of the products thereof is diminished; the contentio'n being that for the highestefficiency the oil about the movable switch-members should be quiet at the moment said members are operated to break the circuit.

The essential object of this invention is to provide for widely separating the submerged switches from each other, so that there is surrounding'each a large body of oil which will be quiet at the moment it is operated. In the present embodiment of my invention the main switches are arranged near the top of the body of oil which is contained in the oil-receptacle, and the auxiliary switches are arranged near the bottom of said body of oil, so that there is a large body of oil between them, and the oil surrounding each is not disturbed by the operation of the other. Furthermore, owing to the fact that the main switches Specification of LettersPatent.

Application filed June 17,

1911. Serial No. 633,698. 1

' are normally shunted by the auxiliary are arranged in difierent vertical planes, as

more fully insure the carrying out of the ideas abovestated.

ing parts shall be arranged upon and supported by the cover of the oil-receptacle, and, hence, in the present embodiment of my invention terminal-bars are provided, which extend through the cover, to which the stationary main and auxiliary switchmain switch-members below but near the top of: the body of oil, and to support the stationary auxiliary switch-members near the bottom of the body of oil, and said terminal-bars are? insulated throughout their length or substantially so.

In the present embodiment of my invention the movable-members of the main switches are resilient and both members of the auxiliary switches are non-resilient. The movable-members of said auxiliary swltches comprise longitudinally movable rods which will not mechanically'disturb the oil surrounding them, and the stationary-members thereof comprise rings having holes through them to receive said rods and having pressuredevices which act to move the rods in a lateral direction into firm engagement with one sidewall of the hole through the rings.

, While herein the operating parts .are' all connected with the cover of the oil-receptacle, the actuatingmechanisin for the movable-members of the switches is entirely separated by a cap, which is-detachably connected with said cover, and which is disso that said mechanism may beseparately removed in assembled condition, if desired.

A partition Wall, of special construction is Patented Jan. 23, 1912.

invention the main and auxiliary switches well as in different horizontal planes, to

It is very desirable that all of the operat posed above an elongated slot in said cover,

members are connected, .said bars being of suitable length to support the stationary arranged between the auxiliary switches,

which extends from side to'side of the oilreceptacle or thereabout. In view of the fact that all of the-operating parts are connected with the cover of the oil-receptacle, it is possible to make repairs without entirely removing said operating parts, by lifting the cover more or less, and herein means are provided for thus lifting the cover which also admit-s of the cover being entirely removed. i

Figur '1 is an end receptacle being broken away. Fig. 2 is a vertical section of the switch shown in Fig;

1 taken on the dotted line 2 2, Fig.1. Fig.

3 is a plan view and partial section taken 'on the dotted line 3 3, Fig. 2. Figs. 4., 5,

6 and 7 are enlarged views of one of the auxiliary swltches. F1g. 8 1s a sectional view of the insulating guide for the plunsubmerged, the oil partially filling the receptacle, as indicated in Fig. 1, so as to leave an expansion chamber above the oil at the top part of the receptacle.

11 is the cover of the receptacle which is detachably connected thereto by any suitable means. This cover is of a very substantial construction,.in order that it may support all the operating parts of the switch. On the under side of-"the' cover 11 a frame is secured which supports the operating parts, consisting essentially ofvertical channel-iron bars 1.2, four in number, attached at their upper ends to the cover, horizontal cross-bars 13 connected at their ends to the bars 12, and two flat horizontal boards or plates 14 and 15, vof wood, supported upon said cross-bars. A doublebreak' switch 'is'here shown, and two pairs of terminal-bars are employedwhich extend being here shown, are designed to bridge down through the coverand are connected with the stationary main and auxiliary switch-members, but my invention is applicable to a single-break switch and if de sired but one pair of terminal-bars need be .66 employed. One terminal-bar of each pair is short, but ,long enough to extend below the surface of the body of oil, and the other terminalbar is formed with an extension,/

making it long enough to extend nearly to the bottom of the body of oil, and said shortand long terminal-bars support .the

elevation of an electric switch embodying this invention, the 'oil- .ranged -stationary main switch-members near the top of the body of oil "and the stationaryauxiliary switch-members near the bottom of the body of oil.

The short terminal-bar 20 is screw-threaded at its upper and lower ends and its upper end portion extends through a collar 25 and tube and arranged one in continuation of the other. The collar 25 extends through a hole in the cover, and has perforated cars 27, ar-

aboye the cover, which receive screws 23 by which the collar is attached to 26, both of insulating material,

the cover. llhe upper threaded end of the bar is designed to receive the terminal of a c1rcu1t;w1re,' but may recelve upon it, as

here shown, a nut 29, which rests in a socket formed in the upper, end of the collar. The lower threaded end of thebar receives upon it a pair of nuts 30, and one end of a plate 32, which is arranged between said nuts; and the lower end of the tube 26, engages one of said nuts and is held between said nut and the collar 25.- The plate 32. serves is one of the stationary main switch-memers. similarly constructed and insulated and sup ports at its lower end one end of another plate 33, which latter serves asithe other stationary main switch-member. The long terminal-bar comprises a short bar -21 constructed ,like the aforesaid short terminalbars and similarly insulated, and having nuts at its lower end between which is arranged and supported the other end of said stationary main switch-member 32; and an extension bar 35,.th'e upper end of which is screw-threaded and enters a screw-threaded socket formed in the lower end of said short bar, thereby connecting them together. The lower end of the extension bar- 35 is threaded and receives upon it a pair of nuts 36, and one end of a conducting plate 37, which is held in ,place by said nuts. The extension bar is incased in a tube 38 of insulating material. The other long terminalbar is similarly constructed and insulated, comprising the short bar 23,having an ex The other short terminal-bar 22, is

tension bar 39, and supporting the other end of the stationary main switch-member 33,

is held in place by said nuts.

The movable main switch-members, two

the stationary main switch-members 32 and 33, and, each may consist of a laminated and one end of a conducting plate 4.0, which bar or brush ll, with a resilient strip superposed thereon, the ends of said brush and strip engaging said plates 32 and 33. Said members 41 are connected loosely by suitable means to a cross-bar 45, which is fixedly attached to the lower end of an up- 11, permittlng up and into and out of engagement with the stationary main switch-members.

The conducting plate 31, which is connected with the extension bar 35, rests upon.

and is attached to a block 50, of insulating material, which is supported upon the frame, and the outer on free end bears the stationary auxiliary switch-member. Said switch-member comprises a ring 'or block 51, of conducting material, having a quadrangular hole 52 through it, or a hole made other than round, and it has a bell-mouthed or tapering entrance to said hole, from above, and said ring rests upon the plate 37, above a hole therein, and is'secured to said plate by screws or otherwise. Said ring has a pair of downwardly extended arms 53, 53, arranged at opposite sides of the hole, which project down through the hole in the plate 37, and said arms have attached to them, on their adjacent faces. and at their lower ends, fiat springs 51, there being two 'such springs attached to each arm and arranged side by side,'and said springsbear at their upper ends small blocks 55, thetid-v jacentfaces of which are made flat and their upper ends rounded to form a tapering entrance to the space between the two pairs of blocks from above.

The auxiliary switch-member is made as a rod or plunger 60, of small diameter, so that it will not act to mechanically disturb the oil surrounding it when moved, and, as here shown, said rod 60. has connected with it, at its lower end, a piece 61, quadrangular in cross-section, or otherwise shaped to loosely fit the hole in the stationary member. Said rod extends through and is guided by an insulating bushing secured to the board 14, and its upperend is connected with one end of the cross-bar 45, so that it will be moved vertically by said cross-bar. \Vhen the cross-ban is in its lowermost position, as shown in Fig. 2, the end-piece 61 will occupy aposit-ion in the hole in the ring and between the two pairs of blocks 55. The oil is not disturbedmechanically by a movement of the plunger-rod until permitted to flow beneath the end thereof, at which time it acts to reduce the arc, and not being disturbed mechanically at such time is in the best possible condition to perform its function. The bushing throughwhich the plunger rod extends is composed of two parts 65 and 66, the part 65 extending up through a shouldered hole 'in the -board.1-l,

and having a frusto-conical, end portion, and the part 66 having a socket in its under side to receive said end portion, and bearing at its lower end upon the board 14. A metallic tube 67 is placed within the two-part insulating bushing, which ismade longer than the bushing and projects therefrom at each end, and its ends'are threaded to reof the bushing and the tube are secured together and alsoheld in fixed relation to the board 14. The plunger-rod slides freely in said bushing. By arranging the auxiliary switch-members near the bottom of the body of oil which, is herein permitted, by the employment of the long terminal-bars, the heat energy of the products of the are formed upon disengagement of the members thereof will be sufiiciently dissipated by-the oil, ,so that the expansion chamber which is providedz at the top of the body'of oil will adequately take care of the gases which rise from the oil. There is connected with the conducting-plate 40, a similarly constructed stationary auxiliary switchmember 70, with which cooperates a. similarly constructed plunger-rod 71, which extends through a bushing 79., connected with the board 11, and is'connected to the end of the cross-bar 45, opposite the plunger-rod 60. The invention, however, is not limited to the employment of main and auxiliary switches of any particular construction, the forms here shown being for the purpose of illustrating one embodiment of my invention.

The actuating-mechanism for theswitch is entirely supported by a cap 80, secured to the cover 11, above an elongated hole therein. Said actuatinganechanism involves an arm 81, slotted at its outer end to engage a laterally extended pin 82 on the upright bar 46, aIpivot-shaft 83, to which said arm is connected, toggle-levers 84, 85, loosely connected to said arm 81, at one end and secured to a pivot-shaft 86, at the other end, an arm 87 secured to said pivot-shaft 86, a link 88 connecting said arm 87 with one arm 89 of a bell-crank lever, the other'arm 90 of said bell-crank lever being loosely connected to a rod 91, which is connected with suitable tripping-mechanism, by which the mechanism is released, springs 92, 93, which encircle the end portions of' the pivot-shaft 83, which are connected at one end with the shaft and at the other end to the support for the shaft, and which, when permitted, act

to turn the shaft in one direction and lift the arm 81. The full and dotted line positions shown in Fig. 2, represent the two positions of the actuating-mechanism.

According to the spirit of my invent-ion it is quite important that the actuatingmechanism shall be entirely supported by the cap 80, so that upon removing said cap said mechanism is removed with it, but the construction of the mechanism itself may be changed, as required.

To more fully insure the separation of the auxiliary switches, a heavy Vertical par tit-ion 100 is arranged between them, which extends from side to side of the oil-receptacle, and from the lower board 15 to the upper board 14. Said partition may be made double, and composed of strips of wood secured together, those on one side being arranged vertically and those on the; other side being arranged horizontally, and the upper and lower ends of the partition may be held against displacement by corner irons secured to the boards 14; and 15.

The cover 11 has eyes 110 secured to it,. adapted to be engaged by hooks connected with a block and. tackle 112 suspended from a crane 113, adapted to be connected to brackets 11 1 on the side of the oil-receptacle, and by operating said block and tackle in the usual manner said cover and parts connected therewith maybe lifted more or less, as desired, or may be entirely removed from the receptacle.-

1. In an electric-switch, an oil-receptacle, stationary and movable main switchmembers arranged below but near the top of the body of oil, stationary and movable auxiliary switch-members arranged near the bottom of the body of oil, and means to move the movable switch-members, substantially as described.

2. In an electric-switch, an oil-receptacle having a cover, a short and a long terminal bar extending through the cover of the receptacle and down into tlTe body of oil, the short bar terminating a short distance below the top of the body of oil and the long bar terminating near the bottom of the body of oil, a stationary switch-member connected at one end to the lower end of said short terminal-bar and at the other end to an intermediate part of the long terminal-bar, and another stationary switch-member connected to the lower end of the long terminal-bar, switch-members movable into and out of engagement with said stationary switch-members, and means to move them, substantially as described.

3. In an electric-switch,v an oil-receptacle, stationary switch-members,.ai1d a mov-.

able switch-member therefor, arranged near the top of the body of oil, stationary auxiliary switch-members, and movable switch-members therefor, arranged near the bottom 'of the body of oil, terminal-bars extending through the cover of the receptacle to which said stationary main switchmembers are connected, two of said bars having downward extensions which terminate near the bottom of the body of oil, and conducting-plates connected to the lower ends of said extensions bearing the stationary auxiliary switch-members, substantially as described.

4. In an-electric-switch, an oil-receptacle, stationary main switch -members, and a movable switch-member therefor, arranged near the top of the body of oil, stationary auxiliary switch-members and movable switch-members therefor, arranged near the bottom of the body of oil, terminal-bars extending through the cover of the receptacle to which said stationary main switch-members are connected, two of said bars having downward extensions which terminate near the bottom of the body of oil, conductingplates connected to the lower ends of said extensions bearing the stationary auxiliary switch-members, and blocks supported on a into the body of oil and terminating, re-

spectively, a short distance below the top and near the bottom of'the body of oil, a stationary .main switch-member and a stationary auxiliary switch-member'supported by said terminal bars, one below but near the top, and the other near the bottom of the body of oil, and switch-members borne by a cross-head,' movable into and out of engagementwith said stationary switch-members, substantially as described.

6. In an electr1c-switch, an oil receptacle, a stationary main switch-member arranged below but near the top of the body of oil, a stationary; auxiliary switch-member arranged nearthe bottom of the body'of oil, a movable main switch-member arranged below but near the top of the body of oil to engage said stationarymain switchsm'ember, a support therefor, and a movable auxiliary switch-member comprising a rod, connected at its upper end to said support, which extends downinto the body of oil to engage said stationary auxiliary switchmember,

GEORGE A.- BURNHAM. Witnesses: i Y

B. J/NoYEs H. B. DAVIS. 

